A method as mentioned above is known from U.S. Pat. No. 5,034,007, which allows a top sheet having leg openings to be manufactured essentially without waste of top sheet material. However, by such a method a seam along the longitudinal centre line of the top sheet material will result. Such a seam is visible for the user and must therefore be carefully manufactured to have an aesthetic pleasant appearance. Furthermore, it would be desirable not to have a seam in the area of the top sheet being occupied by an absorbent body in the end product, such as a disposable diaper for babies or adults. The presence of a seam in the middle of the top sheet, i.e. the area which emitted urine is most likely to hit, could decrease the acquisition properties of the top sheet in this area and leads to an increased risk for leakage.